Optoelectronic characteristics of a near infrared light photodetector based on a topological insulator Sb2Te3 film

In this study, we present a near infrared (NIR) light photodetector based on a topological insulator antimony telluride (Sb2Te3) film, which was grown on sapphire by molecular beam epitaxy (MBE). Electrical analysis reveals that the resistance of the topological insulator decreases with increasing temperature in the temperature range of 8.5-300 K. Further optoelectronic characterization showed that the as-fabricated photodetector exhibits obvious sensitivity to 980 nm light illumination. The responsivity, photoconductive gain and detectivity were estimated to be 21.7 A/W, 27.4 and 1.22 x 10(11) Jones, respectively, which are much better than those of other topological insulators based devices. This study suggests that the present NIR photodetector may have potential application in future optoelectronic devices.